Carbon nanotubes (CNTs) are allotropes of carbon having a generally cylindrical nanostructure, and have a variety of uses in nanotechnology, electronics, optics and other materials sciences. CNTs are both thermally and electrically conductive. Due to these properties, CNTs can be used as heaters to prevent icing on aircraft or other vehicles. Other carbon allotropes, such as graphene or graphene nanoribbons (GNRs), can also be used for heating or de-icing. Graphene has a two-dimensional honeycomb lattice structure, and is much stronger than steel, but is still electrically and thermally conductive. GNRs are strips of graphene with ultra-thin widths. Carbon allotrope heaters are uniquely beneficial for de-icing because of their high efficiency, light weight and ability to be molded into specific shapes, and durability.
The application of heaters made of CNTs, graphene or GNRs to aircraft is complicated by the necessity of connecting the heaters to a power source. Carbon allotropes cannot be wired via soldering to a power source. Generally, CNT heaters are mechanically attached to a metallic bus bar, which in turn is wired to electronics that can provide energy or record data. Previously, other types of heaters that could be more easily attached to a bus bar or electronics were preferred; or carbon allotrope heaters were attached to electronics through mechanical methods such as clamps. These methods did not provide for solderable wire connections to carbon allotrope heaters, and allowed wiring attachments to be delaminated due to coefficient of thermal expansion (CTE) mismatch in thermal cycling environments.